Radial Nerve Palsy

Radial Nerve Palsy

Low Radial Nerve Palsy – finger extension, thumb extension

– anatomic deficits to the: – anatomically intact:
extensor carpi radialis brevis extensor carpi radialis longus
extensor digitorum communis brachioradialis
extensor digiti minimi flexors / pronator teres
extensor indicis
extensor pollicis longus
abductor pollicis longus
extensor pollicis brevis
supinator

– functional deficits: – functionally intact:
finger extension wrist extension/radial deviation
thumb retropulsion – extension/abduction

The primary functions to be restored in the low radial nerve palsy are extension of the digits and extension and radial abduction of the thumb.

Transfers:
Finger extension: FCU to EDC
FCR to EDC
FDS 3 to EDC and FDS 4 to EIP and EPL
Thumb extension/abduction: Palmaris longus to re-routed EPL (Riordan)*
FCR to EPL
Wrist extension (if needed): Pronator teres to ECRB

– in general, at least one of the strong wrist flexors should not be sacrificed, otherwise you may develop an extension deformity at the wrist which will limit finger extension. (ie. don’t harvest palmaris longus, FCU, and FCR!)

* by transposing EPL around Lister’s tubercle and rerouting it along the radial side of the wrist in line with the first metacarpal, palmaris longus can be attached to it in a straight line.

– note: when taking FCU, the muscle belly often extends almost to its tendinous insertion and is anchored down to the surrounding fascia – this makes it hard to mobilize without dissecting off the muscle

pg 3571 and 3572 describe how to do the FCU to EDC and palmaris longus to EPL transfers.

High Radial Nerve Palsy – finger extension, thumb extension, wrist extension

– anatomic deficits to the: – anatomically intact:
brachioradialis flexors / pronator teres
extensor carpi radialis longus
extensor carpi radialis brevis
supinator
extensor digitorum communis
extensor digiti minimi
extensor indicis
extensor pollicis longus
abductor pollicis longus
extensor pollicis brevis

– functional deficits: – functionally intact:
finger extension wrist flexion
thumb retropulsion – extension/abduction
wrist extension

The primary functions to be restored are finger extension, thumb retropulsion, and wrist extension.

Transfers:
Wrist Extension – pronator teres to ECRB
Finger Extension – FCU to EDC
FCR to EDC
FDS 3 to EDC and FDS 4 to EIP and EPL
Thumb Retropulsion – palmaris longus to EPL re-routed